Heavy equipment and machinery frequently require repair and it is generally preferable that such repair be done in the field rather than transporting the machinery or equipment to a suitable repair facility as this reduces the associated time and cost required for repair. One of the most commonly required repairs for large machinery or equipment is the repair or refurbishing of a bore, that is, a circular opening that supports an axle or a shaft, for example, as these circular openings eventually become damaged or worn for a variety of reasons, including mechanical wear of the parts, thereby resulting in a need to restructure or reconstruct the bore to the proper diameter and shape. It may also be desirable to modify a bore for a number of reasons, such as reconstructing the bore to have a slightly larger or smaller diameter to accommodate a different sized shaft or axle.
The repair of a damaged or worn bore or the modification of a bore for any reasons typically involves first rebuilding the interior surface of the bore by deposition of a metal, typically by a welding or a flame deposition process, and the subsequent boring and machining of the rebuilt surface to reduce the rebuilt surface to the precisely required internal diameter. These operations are typically performed in the field by a portable boring machine which has a boring bar that is inserted into the bore to be repaired. The boring bar is typically supported on bearings, located on each side of the bore being repaired, and typically supports one or more exchangeable tools for repairing/refurbishing the bore, such as a welding head or a variety of cutting or machining tools for machining the surface of the bore being repaired.
The arrangement of the boring bar, supporting one or more bore repair tools and supported at each opposed end thereof by bearings, provides radial support and rigidity for the cutting or machining tools that is necessary for accurate reconstruction of the bore, but also presents other problems and shortcomings. For example, and in particular, the accurate reconstruction of a bore requires the accurate guidance of the mounted bore repair tool or tools through the bore to achieve the desired bore diameter and alignment as well as the desired machined finish for the interior surface of the bore.
The present invention provides a solution to these and other related problems of the prior art.